The present invention is generally directed to micro and nano-sized particles formed of semiconductor compounds, thermoelectric compositions formed of such particles, and methods for their synthesis.
Group IV–VI binary semiconductor materials are currently of interest for use in thermoelectric applications, such as power generation and cooling. For example, PbTe-based compounds can be used in solid-state thermoelectric (TE) cooling and electrical power generation devices. A frequently utilized thermo-electric figure-of-merit of a thermoelectric device is defined as
      Z    =                            S          2                ⁢        σ            k        ,where S is the Seebeck coefficient, σ is the electrical conductivity, and k is thermal conductivity. In some cases, a dimensionless figure-of-merit (ZT) is employed, where T can be an average temperature of the hot and cold sides of the device. It has also been suggested that nanostructured materials can provide improvements in a thermoelectric figure-of-merit of compositions incorporating them.
Accordingly, there is a need for methods of synthesizing nanostructured semiconductors from Group IV–VI materials. There is also a need for such synthetic methods that provide high yields and can be readily implemented. Moreover, there is a need for improved IV–VI micro and nanostructures that would exhibit enhanced thermoelectric properties.